A fuel cell vehicle is a vehicle which obtains driving force by a motor using electricity generated when hydrogen reacts with oxygen. The fuel cell vehicle is generally equipped with a hydrogen storage system, and recent trends equip such a vehicle with a commercialized hydrogen storage system having a high-pressure capability of 700 bar. Pipes and fittings, which may endure various pressure levels from high pressure (700 bar) to low pressure (1 bar), are present between a high-pressure hydrogen storage system and a fuel cell stack. The performance for sealing gas, such as hydrogen, is one of the principal factors related to efficiency and safety. In particular, the sealing of a fuel tank valve, which serves to discharge hydrogen stored in a fuel tank, is a very important factor related to the overall safety and efficiency of vehicles.
In a conventional fuel cell system including components such as a fuel tank and a stack, the flow rate in a passage for connecting the components and the size of a purge valve for purging the pressure in the stack are restricted. Accordingly, in order to relieve the pressure of the entire system, a separate pipe is connected to the system after a supply pipe for a vehicle is removed therefrom. However, when leakage occurs in the system, it is difficult to eliminate the leakage without removing the high-pressure/supply pipe.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.